[repository] ldap-feed source. Closes #2086984 datafeed based source which copy a subtree of the ldap directory into the system database. Authentication still go through ldap though. Pros: * don't need temporary tables and such for multi-sources RQL queries execution * much more flexible to enhance / configure behaviour (you simply have to replace the parser) * run better when ldap isn't reachable Cons: * no more 'on the fly' discovery of users (though a user authenticating itself will be automatically added if it doesn't exist in the db yet) * synchronization may be heavy if there are a lot of users A new cw.server.ldaputils containing code in common between former ldapuser and new ldapfeed sources has been introduced. Also ldapuser source now uses url instead of custom host/protocol option so it looks like a datafeed source (could be improved).

change_attribute_type('CWCache', 'timestamp', 'TZDatetime')
change_attribute_type('CWUser', 'last_login_time', 'TZDatetime')
change_attribute_type('CWSource', 'latest_retrieval', 'TZDatetime')
drop_attribute('CWSource', 'synchronizing')
add_attribute('CWSource', 'in_synchronization')